I've played with a Samsung Tab 10... it looks nice, but feels a bit cheap. The back is plastic that flexes (thin and lightweight), it costs the same or a bit more than an iPad. The so-so support of Samsung doesn't help.
Android tablets will always be weak because they don't have Apple's eco-system. I still think that MS's entry into the tablet market with WinMobile 8 will eat into Android sales big time. ThinkPads Tablet looks very nice... but again, all the weakness of Android.
When you look at stores, its Ipad and tablets. Walmart has iPad signs on their doors. In the electronics dept. They have more apple stuff than all the others. Thing about apple, all the icrap stuff is compatible, same standard connector - which is easier to use than the Mini-USB typically used on everything else.
ASUS is the only Android maker that seems to make a good dent in the market, the transformer looks great, works great and easy add-ons is why people like them... and they do actually sell.